Door assembly for an axial-flow combine

ABSTRACT

A door assembly for an axial-flow combine having a crop receiving and generally tubular rotor casting defining an elongated axis, a rotor coaxially disposed within the casing, and a vaned impeller arranged at a forward end of the rotor. The door assembly extends across and at least partially closes a forward open end of the casing. At least a portion of the door assembly has a surface configuration extending circumferentially about its outermost edge for positively moving crop material axially rearward through the rotor casing to reduce crop material repeat on the downward rotational direction side and improving endwind efficiency.

FIELD OF THE INVENTION

The present invention generally relates to combines and, moreparticularly, to an axial-flow combine having a door assembly configuredto positively move crop material rearwardly toward threshinginstrumentalities on a rotor of the combine.

BACKGROUND OF THE INVENTION

A common and well known form of harvesting machine is a rotary combine.Rotary combines are available in various designs and models to performthe basic functions of harvesting, threshing, and cleaning of grain andother crop materials.

A typical combine includes a crop harvesting apparatus which reapsplanted grain stalks and then feeds the grain stalks to a separating orthreshing apparatus. The grain stalks or other crop harvested in thefield is rearwardly moved from the crop harvesting apparatus andintroduced to a threshing assembly by a feeder mechanism.

In axial-flow combines, the threshing assembly includes a generallytubular rotor casing mounted on a frame of a combine and a driven rotordisposed within the casing in co-axial relationship therewith. The rotorand casing have cooperating threshing instrumentalities arranged thereonfor separating and threshing grain from material other than grain. Insuch a combine, which has been available for a number of years, thegrain is threshed several times repeatedly, but gently, as it spiralsaround the rotor and passes through openings in the rotor casing.

The ability to transfer material from the feeder mechanism to the rotorassembly is a key factor in efficient and effective combine operation.To enhance the transfer of crop material, some axial-flow combines,configure a forward end of the rotor casing with an outwardly flaredfunnel-like frusto-conical transition section. The transition sectionsurrounds a vaned impeller arranged at a forward end of the rotor.

At the discharge end thereof, the feeder mechanism introduces acontinuous mat of crop material, having a width approximately equal tothe width of the open end of the transition section, to the rotorassembly. The vaned impeller receives material in an undershot mannerfrom the feeder mechanism and moves the material radially outward towardthe transition section. The inner surface of the transition sectioncombines with the impeller in moving the crop material axially rearwardtoward the threshing instrumentalities on the rotor.

Since there is considerable backlash of material which is "chewed" fromthe mat of crop material issuing from the feeder mechanism, conventionalaxial-flow combines provide a planar end wall or door transverselyextending across a forward end of the rotor casing to confine the cropmaterial which is fed into the rotor casing. Residual crop materialwhich is not moved axially rearward toward the threshinginstrumentalities on the rotor tends to whirl about the face andperiphery of the impeller and reduces combine efficiency. Besidestending to wrap about a forward bearing mount for the rotor assembly,such residual crop material tends to create a backfeed problem for thefeeder mechanism. As will be appreciated, such problems hinderoperativeness of the combine thereby reducing combine capacity.

Where a planar end wall is employed, it has been found that the backlashof crop material impacts against such wall and builds up thereon.Ultimately, this residual crop material forms a circular cake whichclogs the impeller due to the upthrust of material on one side of therotor casing and the downthrust of material on the other side thereof.Thus, a rotating circular disk of material is created within the rotorcasing in advance of the impeller. As this disk becomes thicker, iteventually establishes a solid circular mat which can no longer rotateand, ultimately, causes the engine to stall. As will be appreciated,moist crop materials further aggravate the problem. To clean and clearthis problem, of course, requires valuable time which is a premiumduring a harvesting operation.

Therefore, there is a need and a desire for a device which improves therearward movement of crop material toward the threshinginstrumentalities on the rotor in a manner reducing or avoiding backfeedto the feeder mechanism and prevents crop from wrapping about the frontrotor bearing.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides an improvement overconventional axial-flow combines having a generally tubular rotor casingdefining an elongated axis, a rotor disposed within the casing incoaxial relationship therewith for separating and threshing cropmaterial as the rotor is driven, and a vaned impeller arranged at aforward end of the rotor. The improvement to such combines includes adoor assembly extending across and at least partially closing a forwardopen end of the rotor casing. About a periphery thereof, at least aportion of the door assembly has a ramped configuration which positivelymoves crop material axially rearward through the rotor casing in amanner substantially eliminating heretofore known feedback problems.

In a preferred form of the invention, the rotor casing has an outwardlyflared funnel-like frusto-conical transition section arranged to receivecrop material from a feeder mechanism. The vaned impeller and thetransition section on the rotor casing are sized relative to each otherto define an annular space therebetween through which crop material isfed. A series of spiral transport vanes are secured to the inner surfaceof the transport section to facilitate rearward crop material movementtherethrough.

The ramped configuration on the door assembly directs the crop material,as it reaches the peripheral limits of the door assembly, to sliderearwardly into the open annular space between the vaned compeller andthe transition section of the rotor casing. The door assembly providesan open area extending along the upper rotational direction side of theimpeller to allow room for crop material to endwind over a leading edgeof the impeller plan of rotation. The size of the open area decreasesfrom the upper rotational direction side to the downward rotationaldirection side of the impeller to induce crop material to moverearwardly through the impeller area of the rotor.

In a preferred form, the door assembly has a ramped portion peripherallyextending about its outer edge to induce the crop material, as itreaches its peripheral limits, to slide rearwardly toward threshinginstrumentalities on the rotor. The configuration of the ramped portionchanges as a function of its angular disposition about the casing toprovide maximum directional influence to the crop material and asubstantially consistent entrance clearance at the impeller tip orbit.Preferably, the ramped surface has a convex configuration extendingabout the peripheral edge of the door assembly. In a most preferred formof the invention, a ramped surface portion of the door assembly extendsbelow the axis of the casing to positively impart rearward direction tothe crop material throughout its travel about a forward end of the rotorcasing.

The door assembly is preferably configured with an anti-wrap vane whichsubstantially encompasses a front bearing mount for the rotor. This vaneinhibits crop material from wrapping about the bearing mount and therebyreduces downtime for the combine.

The provision of such a door assembly reduces crop material repeat onthe downward rotational direction side of the impeller by improvingendwind efficiency of the impeller. Positively imparting rearward axialmovement of the crop material at a forward end of the impellerfurthermore reduces backfeed to the feeder mechanism. Another advantageof the door assembly according to the present invention is a reductionin the power consumption for the rotor and more efficient combineoperation. Moreover, a door assembly embodying features of the presentinvention reduces those areas at the forward end of the rotor in whichcrop material may accumulate and, ultimately, plug operation of therotor assembly.

Numerous other features and advantages of the present invention willbecome readily apparent from the following detailed description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view, partially broken away, of acombine equipped with the present invention;

FIG. 2 is an enlarged longitudinal sectional view of a forward end of arotor assembly for the combine illustrated in FIG. 1;

FIG. 3 is a front elevational view schematically illustrating a forwardend of the rotor assembly of FIG. 2;

FIG. 4 is a rear sectional view taken along line 4--4 of FIG. 2;

FIG. 5 is a longitudinal sectional view taken along line 5--5 of FIG. 4;

FIG. 6 is a longitudinal sectional view taken along line 6--6 of FIG. 4;and

FIG. 7 is a longitudinal sectional view taken along line 7--7 of FIG. 4.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings a preferred embodiment of theinvention which is hereinafter described, with the understanding thatthe present disclosure is to be considered as an exemplification of theinvention, and is not intended to limit the invention to the specificembodiment illustrated.

Referring now to the drawings, wherein like reference numerals indicatelike parts throughout the several views, there is shown in FIG. 1 aself-propelled combine 10 having front drive wheels 12. The combine 10further includes a body 14 having an interconnected supporting structureor frame which defines an operator station 16.

The combine is operatively powered by an engine (not shown) suitablysupported and housed within body 14 and which provides driving power forthe combine. The transfer of rotation and power from the engine tovarious driven components of the combine is by conventional devices andcould include fixed or variable belt or chain drives which are not shownor described herein but are well known in the art.

At its front end, the combine is provided with a crop harvestingapparatus or header 18 which can be of suitable design. The cropharvesting apparatus 18 cuts and directs crop material toward a cropfeeder mechanism 20. The crop feeder mechanism 20 preferably includes aconventional chain and slat conveyor that advances crop material in acrop layer or mat toward an axial-flow rotor assembly 22 which acts toseparate and thresh grain from material other than grain.

The rotor assembly 22 is conventionally supported inside the body 14 ofthe combine 10. As is the case in connection with axial-flow combines ofthe type hereunder consideration, the rotor assembly 22 embodies cropthreshing and separating means in a single unit. More specifically, therotor assembly 22 includes a generally tubular rotor casing or housing24 mounted in a fore-and-aft direction in the combine along an elongatedaxis and a generally cylindrical rotor 26. The rotor casing 24 and rotor26 have cooperating threshing instrumentalities arranged thereon forthreshing and separating grain from material other than grain.

The rotor 26 is journalled in generally coaxial relationship within thecasing 24 by a front bearing 28 and a rear bearing (not shown). Thefront bearing 28 is supported by a transverse rotor supporting member 30which extends across the forward end of the rotor casing 24 and isrigidly secured to the frame of the combine.

Turning to FIG. 2, at its forward end, the rotor casing 24 has anopen-ended transition section 32 which may be regarded as a forwardextension of the tubular rotor casing 24. The transition section 32 isarranged in crop receiving relation with the feeder mechanism 20 (FIG.1). In the preferred embodiment, transition section 32 is provided withan outwardly flared funnel-like frusto-conical configuration which issuitably secured to the support member 30. As illustrated, thetransition section 32 has a decreasing cross-sectional area in adownstream direction extending between fore-and-aft ends thereof. Theconfiguration of the transition section functions to "funnel" the cropmaterial axially rearwardly through the rotor casing.

As shown in FIG. 2, a vaned impeller 34 is arranged within thetransition section 32 for rotation with the rotor 26. The impeller 34includes a plurality of circumferentially and equally spaced vanes orblades 36. Each blade 36 is rigidly secured along an inner edge to amounting surface on the rotor 26. Each blade 36 has an outer workingedge having a declining slope in the downstream direction of the rotor26. Between its inner and outer edges, each blade 36 preferably has asomewhat twisted form configured to draw air and crop material into thetransition section 32 and move it toward the threshing instrumentalitieson the rotor.

When the rotor 26 is driven, the working edge of the blade generates acone frustum trace having a slant angle which is substantially equal tothe slant angle of the frusto-conical transition section 32 of the rotorcasing 24. A small annular clearance or opening 38 is defined betweenthe working edge of the bladed impeller and the inner surface of thetransition section 32. It is through this annular clearance opening thatcrop material is moved axially rearwardly toward threshinginstrumentalities on the rotor assembly. A plurality of spiral transportvanes 40 are supported on an internal wall surface of the transitionsection 32 and extend into the annular opening or space 38 to facilitateaxial rearward movement of the crop material through the transitionsection 32 of the rotor assembly.

In the preferred embodiment, the rotor 26 and, therefore, impeller 34turn in a counterclockwise direction as viewed from a front end of thecombine. Accordingly, crop material issuing from the feeder mechanism 20(FIG. 1) is elevated by the upwardly moving blades 36 which pass acrossthe general plane of the crop material issuing from the feeder. Cropmaterial is propelled outwardly and circumferentially about the forwardend of the transition section by the blades 36. As the blades 36 on theleft side of the transition section descend, fresh crop material,introduced into the path of the blades, is carried downwardly.

According to the present invention, a partially cup-shaped multi-piecedoor assembly 44 extends across and at least partially closes a forwardopen end of the transition section 32. In a preferred form, the doorassembly 44 is releasably secured to the rotor support member 30forwardly of the impeller 34 (FIG. 2). A portion of the door assembly 44extends above and, preferably, below the extended axis of the rotorassembly.

The door assembly has a surface configuration which complements andcoacts with the impeller 34 in positively moving crop material axiallyrearward through the transition section 32 of the rotor assembly 22. Asshown in FIGS. 2, 3 and 4, the door assembly 44 includes a generallyplanar portion 46 arranged forward of the impeller 34 and which extendsradially from the support member 30 and a ramped portion 48 providedabout the periphery of the door assembly 44. As illustrated, portion 46extends away from the support member 30 in a plane generally normal tothe elongated axis of the rotor assembly 24 and has forward and rearwardsurfaces 47 and 49, respectively. In the illustrated embodiment, theramped portion 48 extends from surface 46 and has an axially rearwardconfiguration which extends circumferentially about a forward end of theimpeller 34. Preferably, ramped surface 48 has a convex profile axiallyextending rearwardly toward the rotor.

In a preferred form of the invention, the ramped portion 48 on the doorassembly is configured to accommodate changes in volume as the cropmaterial is advanced about the vaned impeller. As shown in FIGS. 5, 6,and 7, the configuration of the ramped portion 48 changes as a functionof its angular orientation relative to the forward end of the transitionsection.

In planar cross section and as viewed in FIG. 4, the door assembly 44has a gradual involute shape about its peripheral edge to allow room forcrop material to endwind over the impeller leading edge plan of rotationas it advances toward the rotor and defines an open area about theimpeller tip area. The involuted shape of the door assembly decreasesthe open area about the tip of the impeller from the upper directionalside to the downward rotational direction side to induce rearward cropmovement of material toward the rotor.

In a most preferred form of the invention, a portion of the doorassembly 44 extends beneath the elongated axis of rotor casing 24. Aswill be appreciated, the door assembly will be configured to notinterfere with introduction of crop material from the feeder mechanism20 into the transition section 32 of the rotor assembly.

As illustrated in FIG. 4, the door assembly 44 further includes anarcuately formed anti-wrap vane 50. As shown, the anti-wrap vane 50encircles and protects the front bearing 28 from having crop materialwound thereabout.

In operation, the crop harvesting apparatus or header 18 reaps plantedcrop material and delivers it to the crop feeder mechanism 20. The cropfeeder mechanism rearwardly advances and, ultimately, introduces thecrop material into the open-ended transition section 32.

The crop material is discharged upwardly into the transition section 32and the action of the vaned impeller 34 causes most material to move ina radial and rearward spiralling motion through the transition section.The whirling rotary action of the impeller 34 causes other crop materialto likewise move radially outward. Portion 46 of the door assembly 44will confine the crop material and direct same circumferentially outwardtoward the ramped portion 48. The configuration of the ramped portion 48is such that the crop material discharged therefrom is rearwardlydirected into the annular opening 38 thereby reducing crop materialrepeat on the downward rotational direction side by improving endwindefficiency.

Changing the ramped configuration on the door assembly 44 as a functionof its angular orientation relative to the rotor casing provides maximumdirectional influence and consistent entrance clearance at the impellertip orbit. Rearward movement of crop material is further augmented bythe provision of the spiral transport fins 40 provided on the insidesurface of the transition section 32.

Crop material is likewise carried downwardly by the impeller 34 belowthe extended axis of the rotor. In a preferred form of the invention,therefore, the ramped portion 48 extends beneath the longitudinal axisof the casing so as to impart a rearward motion to the crop materialthat is thrust downwardly by the impeller action.

The gradual involuted shape of the door assembly relative to the traceof the impeller blades is provided in appreciation that the volume ofcrop material traversing about the circumference of the impeller willchange. Accordingly, the surface configuration of ramp portion 48likewise changes to accommodate changes in speed and volume of the cropmaterial relative to the angular orientation of the surface relative tothe rotor casing.

The anti-wrap vane 50 inhibits crop material from becoming entangledwith or entrained about the front bearing 28. The anti-wrap vane 50 isconfigured to develop a free flow of material outwardly and away fromthe front bearing thereby inhibiting a buildup of crop material aboutthe front bearing which can ultimately clog the rotor assembly.

From the foregoing, it will be observed that numerous modifications andvariations can be effected without departing from the true spirit andscope of the novel concept of the present invention. It will beappreciated that the present disclosure is intended as anexemplification of the invention, and is not intended to limit theinvention to the specific embodiment illustrated. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

What is claimed is:
 1. An axial-flow combine comprising:a frame havingground engaging wheels for allowing the combine to move over a field; agenerally tubular rotor casing mounted on said frame along an elongatedaxis and provided with an outwardly flared funnel like frusto-conicaltransition section designed for endwise reception of crop material; arotor disposed within said casing in coaxial relationship therewith,said rotor and casing having cooperating threshing instrumentalitiesarranged thereon; a vaned impeller arranged at a forward end of saidrotor and within said frusto-conical transition section; and a doorassembly extending across and at least partially closing a forward openend of said transition section, a portion of said door assembly defininga ramped surface configuration extending at least partially about theimpeller to direct crop material over a leading edge of the impellerplan of rotation and positively move crop material axially rearwardlythrough the transition section of the rotor casing.
 2. The axial-flowcombine according to claim 1 with said rotor being rotatably supportedat a forward end by bearing means, and said door assembly including ananti-wrap vane which at least partially encircles said bearing means toinhibit crop material from wrapping thereabout.
 3. The axial-flowcombine according to claim 1 wherein the ramped surface configuration ofthe door assembly defines a clearance area about the periphery of thevaned impeller which decreases from an upper rotational direction sideof the impeller to a downward directional side of the impeller to induceaxially rearward crop material movement through the transition section.4. The axial-flow combine according to claim 1 wherein at least aportion of said door assembly extends above said elongated axis and atleast a portion of said door assembly extends below said elongated axis.5. An axial-flow combine comprising:a tubular casing having an elongatedfore-and-aft extending axis and an open forward end for receiving cropmaterial; a generally cylindrical rotor axially disposed in said tubularcasing and journalled for rotation within said casing for threshing andseparating crop material as the rotor is driven, said rotor having avaned impeller arranged within and at the forward end of said casing;and a door assembly having generally planar forward and rearwardsurfaces arranged to at least partially close a portion of the openforward end of said casing above the elongated axis of said casing, saiddoor assembly having a ramped portion extending rearwardly away fromsaid rear surface of said door assembly and circumferentially extendingabout a forward end of said impeller for positively moving crop materialrearwardly through the casing.
 6. An axial-flow combine comprising:atubular casing having an elongated fore-and-aft extending axis and anopen forward end for receiving crop material; a generally cylindricalrotor axially disposed in said tubular casing and journalled forrotation within said casing for threshing and separating crop materialas the rotor is driven, said rotor having a vaned impeller arrangedwithin and at the forward end of said casing; and a door assemblyarranged to at least partially close a portion of the open forward endof said casing above the axis of said casing, said door assembly havinga rearwardly ramped surface configured to at least partially extendcircumferentially about a forward end of said impeller for positivelymoving crop material rearwardly through the casing and wherein theramped surface configuration of said door assembly changes as a functionof its angular disposition about said casing.
 7. An axial-flow combinecomprising:a tubular casing having an elongated fore-and-aft extendingaxis and an open forward end for receiving crop material; a generallycylindrical rotor axially disposed in said tubular casing and journalledfor rotation within said casing for threshing and separating cropmaterial as the rotor is driven, said rotor having a vaned impellerarranged within and at the forward end of said casing; and a doorassembly arranged to at least partially close a portion of the openforward end of said casing above the axis of said casing, said doorassembly having a rearwardly ramped surface portion extending below theaxis of said casing and extending circumferentially about a forward endof said impeller for positively, moving crop material rearwardly throughthe casing.
 8. An axial-flow combine comprising:a fore-and-aft extendingmobile frame; material infeed means mounted on the frame; a generallytubular casing mounted on said frame and having an open forward endarranged in material receiving relation to said infeed means; agenerally cylindrical rotor journalled for rotation about a fore-and-aftrotational axis within said casing for acting on the material as therotor is driven within the casing, said rotor having a vaned impellerarranged within said casing at a forward end thereof, said impeller andcasing being constructed and arranged relative to each other to definean annular space therebetween within which material is fed; a doorassembly secured to said frame forwardly of said impeller and havingforward and rearward generally planar surfaces extending generallynormal to said rotational axis to at least partially close the openforward end of said casing without interfering with said infeed means, acircumferential portion of said door assembly complementing said casingand having a ramped surface extending rearwardly away from said rearplanar surface of said door assembly to facilitate material deliveryinto the annular space and rearwardly through the casing.
 9. Anaxial-flow combine comprising:a fore-and-aft extending mobile frame;material infeed means mounted on the frame; a generally tubular casingmounted on said frame and having an open forward end arranged inmaterial receiving relation to said infeed means, said tubular casinghaving an outwardly flared transition section at a forward end thereofwith a series of spiral transport vanes secured to an inner surfacethereof; a generally cylindrical rotor journalled for rotation about afore-and-aft rotational axis within said casing for acting on thematerial as the rotor is driven within the casing, said rotor having avaned impeller arranged within said casing at a forward end thereof,said impeller and casing being constructed and arranged relative to eachother to define an annular space therebetween within which material isfed; a door assembly secured to said frame forwardly of said impellerand lying in a plane passing through said rotational axis to at leastpartially close the open forward end of said casing without interferingwith said infeed means, a circumferential edge of said door assemblycomplementing said casing and having a rearwardly extending rampedportion to facilitate material delivery into the annular space andrearwardly through the casing.
 10. The axial-flow combine according toclaim 9 wherein said ramped portion has a changing configurationdepending upon its annular orientation relative to said casing.